Apparatus for processing photographic materials

ABSTRACT

An apparatus for processing photographic liquid including a processing drum which utilizes and discharges successively received unit charges of photographic processing liquid, a container for storing a unit charge of the liquid to be received by the drum, a heating element for heating the container and a fluid pressure temperature sensor in thermal communication with the heating element and the drum for regulating the temperature of the liquid in the container in inverse proportion to the ambient temperature surrounding the drum.

United States Patent 1,319,047 10/1919 Dalen Inventor Paul Romano Rochester, N.Y.

Appl. No. 698,832

Filed Jan. 18, 1968 Patented May 25,1971

Assignee Eastman Kodak Company Rochester, N.Y.

APPARATUS FOR PROCESSING PHOTOGRAPHIC MATERIALS 6 Claims, 3 Drawing Figs.

U.S. Cl 219/330, 95/89, 219/328, 219/513, 236/91 Int. Cl F24h 1/00 Field of Search 219/360,

References Cited UNITED STATES PATENTS 1,785,426 12/1930 Raymond 236/91 2,428,642 10/1947 Weeks 219/513X 2,611,850 9/1952 Walton i 219/513X 3,150,827 9/1964 Mohn et al 236/91X Primary Examiner-4, V. Truhe Assistant ExaminerC. L. Albritton Attorneys-Robert W. Hampton and John D. Husser ABSTRACT: An apparatus for processing photographic liquid including a processing drum which utilizes and discharges successively receiyed unit charges of photographic processing liquid, a container for storing a unit charge of the liquid to be received by the drum, a heating element for heating the container and a fluid pressure temperature sensor in thermal communication with the heating element and the drum for regulating the temperature of the liquid in the container in inverse proportion to the ambient temperature surrounding the drum.

PATENTED "M2519?! FIG. I

LIQUID mmooucnow TEMPERATURE AVERAGE PROCESSING OPERATION TEMPERATURE 65 7O 75 8O 85 9O AMBIENT TEMPERATURE F PAUL ROMANO INVENTOR.

BY M

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ATTORNEYS APPARATUS FOR PROCESSING PHOTOGRAPIIIC MATERIALS CROSS-REFERENCE TO RELATED APPLICATIONS Reference is made to commonly assigned copending US. Pat. applicationSer. No. 454,543, entitled Tubular Processor, filed May 10, i965 in the name ofRoy D. Porter, and US. Pat. application Ser. No. 698,833, entitled Photographic Processor Having Movement Responsive Rotation Control, filed Jan. 18, 1968 in the name of Einar Jensen.

BACKGROUND OF INVENTION 1. Field of Invention The present invention relates to an improved method for processing photographic materials and to apparatus for use with photographic processors for carrying out the improved method. More specifically, the present invention relates to an improved method of photographic processing which includes tempering the processing liquid in a unique manner prior to the photographic processing operation and to apparatus for tempering such liquids in accordance with the improved method.

2. Description of Prior Art Processing apparatus for photographic materials can be grouped broadly in two general classes. In the first classification are apparatus which are designed to process a large quantity of photographic sheet material at the same time or process a web of photographic material in continuous'operation. This type of apparatus usually has one or more processing chambers which contain relatively large quantities of processing liquid and into which photographic materials are cyclically inserted and removed. In such apparatus the large quantity of liquid is often thermostatically controlled to a predetermined temperature which achieves optimum results for the processing operation. The optimum temperatures of a photographic processing liquid bath are dependent on the particular chemistry of the photographic materials to be developed'and processing liquid used.

In the other general classification of photographic processing apparatus are the types which are intended to accommodate small quantities of photographic materials. In such apparatus, the photographic material is placed in a processing chamber and a unit charge of treating liquid, i.e., a quantity sufficient to process the material then in the apparatus, is introduced into and discharged form the container. Successive unit charges of different liquids can, of course,'be introduced to treat the same sheet. One such processing'apparatus is disclosed in copending US. application Ser. No. 454,543. 1

ln photographic processing using this latter class of processing apparatus, control of the temperature at which the processing operation is conducted has heretofore been less precise then with the first general class of apparatus because of the change in temperature of a unit charge of processing liquid during the processing operation. This temperature change occurs because the processor body absorbs heat from the liquid during the processing operation and transfers heat to the generally cooler air surrounding the processor. Since the ambient temperatures surrounding the processor vary, a constant heat loss factor cannot be determined for the processors.

Accordingly, the obtaining of optimum processing results with such apparatus in processing operations dependent on temperature regulation, has'been difficult.

SUMMARY OF INVENTION lt is therefore an object of the present invention to provide an improved apparatus for processing photographic materials.

Another object of the present invention is to provide an apparatus for use with a photographic processor to facilitate control of temperature at which the processing operation is conducted.

Yet another object of the present invention is to provide a method of processing photographic materials whereby improved control of the processing liquid temperature during processing and hence in improved processing resultare achieved.

Still another object of the present invention is to provide an improved method of processing photographic materials in apparatus of the type adapted to receive unit charges of processing liquid in a processing chamber.

Another object of the present invention is to provide a novel method of processing whereby the temperature of the processing operation can be controlled and optimum results obtained, regardless of changes in ambient temperature conditions around the processing apparatus.

Another object of the present invention is to provide an improved apparatus for use with a photographic processor to regulate the temperature of processing liquid to be introduced in response to changes of the ambient temperature surrounding the processor.

Other objects of the present invention are to provide an improved method of processing photographic materials in a processor adapted to receive successive unit charges of processing liquid whereby a unit charge of liquid is tempered to a predetermined temperature before introduction into the processing apparatus, which predetermined temperature is regulated in response to temperature conditions surrounding the processing apparatus and to provide an apparatus for automatically controlling this tempering operation.

As used herein the terms temper" and tempering refer to conditioning liquids to a specific temperature such as can be effected by the selective transfer of heat to and from the liquid.

These an other objects are achieved by the operational steps and structural means of the present invention. Briefly stated, one mode of the present invention comprises temperinga unit charge of the processing liquid to be used to a predetermined temperature above the temperature at which the chemistry of the photographic paper and liquid produces optimum results. This predetermined temperature is an amount above the optimum temperature such that, with the heat loss and temperature drop which occur during processing, the average temperature during the processing operation is substantially the same as the optimum temperature desired for the chemistry of the processing operation. In order to effect this method, the predetermined temperature must be varied in accordance with changes in the ambient temperature around the processing apparatus because a different liquid-ambient temperature gradient causes different heat loss and would result in a different average-processing-operation temperature. To compensate for changes in ambient temperature and the resulting change of heat loss and temperature drop, the predetermined temperature'at which the liquid is introduced is regulated in a predetennined inverse proportion to ambient temperature around'the processor.

unit charges of processing liquids to be introduced into a processor and a two-probe thermostat which senses the liquid temperature and ambient temperatrue. The thermostat is calibrated to energize the heat transfer means when the processing liquid drops below a temperature (i.e., its desired introduction temperature) which will result in the optimum average-processing-operation temperature for present ambient temperature conditions. When the processing ,liquid reaches the proper introduction temperature for existing ambient temperature conditions, the heating means are deenergized. In this embodiment means are provided for varying the predetermined liquid introduction temperature for a given ambient temperature so as to facilitate processing of photographic materials having chemistry requiring a different average-processing-operation temperature.

BRIEF DESCRIPTION OF DRAWINGS The novel aspects of the present invention will be apparent to one skilled in the art from the following detailed description of the modes of operation and structural embodiments of the invention, with reference to the drawings in which like characters denote like parts and wherein:

FIG. 1 is a perspective view showing a processing apparatus of the type with which the method and apparatus of this invention are adapted foruse and showing one embodiment of the tempering apparatus of the present invention;

FIG. 2 is a schematic diagram showing the control and heating means of the present invention; and

FIG. 3 is a graph showing the controlled relation between the temperature of liquid to be introduced and ambient temperature around the processor provided in accordance with the present invention for one desired average-processingoperation temperature.

DESCRIPTION OF PREFERRED EMBODIMENTS By referringto FIG. 1, a photographic processing apparatus 1, with which the tempering control unit 2 of the present invention can be used, is seen. This tempering control unit can be used with the processor to effect the novel method of the present invention.

The processing apparatus 1 is disclosed in detail in a U.S. Pat. application Ser. No. 698,833 entitled, Photographic Processor Having Movement Responsive Rotation Control and filed on Jan. l8, 1968 in the name of Einar W. Jensen. Generally, this apparatus comprises a processing drum 3 which is adapted. to sequentially receive and use unit charges of processing liquid. The processing drum 3 receives liquid in a vertical position and is rotated on a tiltable frame 4 when moved to the horizontal position shown in FIG. 1. The processing operation occurs during rotation of the drum 3, and after a predetermined time the frame 4 is tilted back to a vertical orientation.- Rotation of the drum 3 then ceases and the used charge of processing liquid is drained from the bottom of the drum while the next unit charge of liquid is introduced through the top of the processor. The different unit charges are'maintained separate by a novel reservoir in the drum 3, not shown. The tempering unit 2 is adapted to condition the temperature of unit charges of processing liquids in accordance with the present invention of introduction into the processor shown; however, it will be appreciated by those skilled in the art that the method and apparatus of the present invention are useful with any unit charge type of processing apparatus. The particular processing apparatus disclosed herein should not, therefore, be construed as in any way limiting the scope of the present invention.

The tempering unit 2 comprises a large reservoir in which one or more unit charge containers 21 of processing liquid can be supported in heat transfer relation with a tempering liquid, e.g., water, in the reservoir 20. The tempering liquid in the reservoir is selectively heated by coils 22 which are located in the reservoir 20 beneath the containers 21.

Referring now to FIG. I and 2 the temperature control means of the present-invention will be described. A thermostat 30 shown schematically within the dotted lines in FIG. 2 is located, in part, within a control box 31 of the tempering unit 2, shown in FIG. 1, and has sensing probes 32 and 33 extending from the control box 31. The probe 32 extends into the reservoir 20 so as to be in sensing contact with the tempering liquid therein. If desired this probe can, of course, be located so as to contact the treating liquids directly. Probe 33 extends through a wall'of the processor housing as shown in FIG. 1 so as'to be close to the external surface of the processing drum 3.

Referring to FIGS. 1 and 2 it can be seen that the sensing probes 32 and 33 are connected by capillary tubes 34 and 35 respectively to a junction 36 and that a single capillary tube 37 connects the junction 36 with a main thermostat housing 38 which is located inside control box 31. The sensing probes 32 and 33 are of the type which exert fluid pressure that is directly proportional to the temperature condition sensed.

Referring to FIG. 2 it will be seen that the capillary tube 37 transmits combined fluid forces from capillaries 34 and 35 to the diaphragm 39 which is located inside housing 38. Switch contact 40 is pivotally mounted in the thermostat 30 and electrically connected to terminal 41 of housing 38. The contact 40 is also connected to the opposite side of diaphragm 39 from the inlet of capillary 37 by plunger 52 as shown in FIG. 2. Spring 42 urges diaphragm 39 against the fluid pressure exerted through capillary 37. Switch contact 44 comprises a circular conductive member which is movable towards and away from contact 40 by means of a threaded nut 46 which extends outside the thermostat housing 38 and control box 31 and is connected to calibrating knob 47. The switch contact 44 remains in electrical contact with terminal 48 of the thermostat housing 38 during movement of calibrating knob 47.

The thermostat 30 is connected in the electrical circuit from source 50 to heating coils 22 at terminals 4l'and 48. An off-on switch 49 is also provided in this circuit.

In operation it can be seen that when switch 49 is closed, combined fluid force of sufficient magnitude form capillaries 34 and 35 will cause the diaphragm 39 to move against spring 42 and that contact 40 will move away from contact 44, thereby opening the circuit from electrical source 50 to the heating coils 22. When the combined force from capillaries 34 and 35 drops below the predetermined force, spring 42 moves contact 40 into engagement with switch 44 and closes the circuit to energize coils 22. It can also be seen that the combined force necessary to open the switch in thermostat 30 can be varied by turningknob 47 to change the distance between contacts 40 and 44.

When calibrating knob 47 has been positioned for a certain average-processing-operation temperature, the operation of the disclosed apparatus is as follows. Probes 32 and 33 respectively sense the existing processing liquid and ambient temperature conditions and exert fluid forces proportional thereto. If the combined force exerted in diaphragm 39 is large enough to open switch 40-44, no heat is supplied to the tempering liquid. This condition occurs when the treating liquid temperature is high enough, considering the ambient temperature around the processor, to produce the proper ,average-processing-operation temperature during processing.

If the ambient temperature drops, the combined fluid force exerted by sensors 32 and 33 decreases and the spring 42 closes switch 4044 to energize the coils 22 and heat the processing liquid. When the processing liquid temperature has increased sufficiently to provide the proper averageprocessing temperature in the changed ambient-conditions, the increased fluid pressure from the probe 32 balances the pressure drop from probe 33 resulting from the ambient temperaturedrop; and the predetermined combined force is again achieved. Switch 40-44 then opens in the manner described above the terminates heating of the liquid. 4

It can be seen that the same relation will apply when ambient temperature rises from an equilibrium condition in that no heat will be transferred to the treating liquid until the temperature has dropped below a lower level because of the increased pressure from probe 33 caused by the ambient temperature rise. This is, of course, in accordance with the object of the present invention since for higher ambient conditions,

processor disclosed herein. It will be appreciated that the straight line representing the relation of ambient and liquid introduction temperatures for the average-processing-operation temperature of 100 F. can be shifted horizontally to maintain other desired average-processing-operation temperatures for the same processor by moving contact 44 of the thermostat.

in order to use the present invention with processors having different heat loss constants it is necessary to empirically determine the liquid temperature drop of a certain time period in that processor and thereby establish a similar straight line relation for use with that processor. Based on the teachings herein, such empirical data can readily be established by one skilled in the art. A thermostat like that disclosed can then be constructed to achieve the established straight line relation, and control for different average-processing-operation temperatures in that particular processor can be maintained in the manner disclosed herein.

EXAMPLE As one example of an application of the novel method of the present invention', a previously exposed, color print paper was developed using the disclosed processor and tempering unit with the thermostat control set for the ambient-liquid temperature relation shown in FIG. 3.

An appropriate unit charge of developer was dispensed into one of the containers 21 and this container 21 was placed in the tempering unit 2. The switch 49 was closed and the tempering unit 2 and charge of liquid were allowed to reach an equilibrium condition.

A photographic sheet was then inserted in the processing drum 3. The drum 3 was placed on the frame 4 and oriented to a vertical position. The paper was first subjected to a tempered water wash in the manner described. Next, developer liquid tempered above the desired average-processing-operation temperature in accordance with the graph in FIG. 3 was introduced into the processor an the processor moved to the horizontal position and rotated for 2 k minutes. The sheet was thereafter successively treated in a similar manner with unit charges of different treating liquids and washes. The results obtained by using the present method of tempering preintroduction temperature of the developer liquid yielded processed photographic prings far superior to prints processed without the controlled pretempering of the present invention.

The invention has been described in detail with reference to preferred modes and embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

lclaim:

1. In combination with a photographic processing apparatus of the type wherein a photographic processing drum is provided for utilizing and discharging successively received unit charges of photographic processing liquid and wherein a container is provided for storing a unit charge of photographic processing liquid to be received by said drum, the improvement which comprises:

means for heating a unit charge of photographic processing liquid within said container; and

means cooperating with said heating means for regulating the temperature of a unit charge of photographic processing liquid within said container in inverse proportion to the ambient temperature conditions surrounding the drum.

2. The improvement as recited in claim I, wherein said drum is provided with a substantial external surface which is exposed to the ambient temperature conditions, and wherein said regulating means comprises:

means for sensing the temperature of a unit charge of photographic processing liquid within said container; and

means for sensing the ambient temperature conditions immediately surrounding said substantial external surface of said drum. 3. The improvement as recited in claim 2, wherein both said sensing means are of the fluid pressure type, said heating means comprises:

an energizable heating element, and said regulating means further comprises:

means for combining the fluid pressure of both said sensing means; and

means, responsive to a combined fluid pressure of predetermined magnitude from both said sensing means, for energizing said heating element.

4. The improvement as recited in claim 3, which further comprises:

means for selectively varying the magnitude of the combined fluid pressure from both said sensing means at which said heating element is energized. 5. The improvement as recited in claim 1, which further comprises:

a reservoir of tempering liquid; and

means for supporting said container in heat transfer relation with said tempering liquid, and wherein said heating means extends into said tempering liquid.

6. In combination with a photographic processing apparatus of the type wherein a photographic processing drum is provided for utilizing and discharging successively received unit charges of photographic processing liquid and wherein a container is provided for storing a unit charge of photographic processing liquid to be received by said drum, the improvement which comprises:

means for tempering a unit charge of photographic processing liquid within said container to a predetermined temperature above that temperature which is optimum for photographic processing; and

means for varying the predetermined temperature of the unit charge of photographic processing liquid within said container in inverse proportion to changes in the ambient temperature immediately surrounding the drum in a manner such that the predetermined temperature exceeds the optimum temperature by an amount resulting in an average photographic processing temperature which is substantially the same as the optimum temperature. 

1. In combination with a photographic processing apparatus of the type wherein a photographic processing drum is provided for utilizing and discharging successively received unit charges of photographic processing liquid and wherein a container is provided for storing a unit charge of photographic processing liquid to be received by said drum, the improvement which comprises: means for heating a unit charge of photographic processing liquid within said container; and means cooperating with said heating means for regulating the temperature of a unit charge of photographic processing liquid within said container in inverse proportion to the ambient temperature conditions surrounding the drum.
 2. The improvement as recited in claim 1, wherein said drum is provided with a substantial external surface which is exposed to the ambient temperature conditions, and wherein said regulating means comprises: means for sensing the temperature of a unit charge of photographic processing liquid within said container; and means for sensing the ambient temperature conditions immediately surrounding said substantial external surface of said drum.
 3. The improvement as recited in claim 2, wherein both said sensing means are of the fluid pressure type, said heating means comprises: an energizable heating element, and said regulating means further comprises: means for combining the fluid pressure of both said sensing means; and means, responsive to a combined fluid pressure of predetermined magnitude from both said sensing means, for energizing said heating element.
 4. The improvement as recited in claim 3, which further comprises: means for selectively varying the magnitude of the combined fluid pressure from both said sensing means at which said heating element is energized.
 5. The improvement as recited in claim 1, which further comprises: a reservoir of tempering liquid; and means for supporting said container in heat transfer relation with said tempering liquid, and wherein said heating means extends into said tempering liquid.
 6. In combination with a photographic processing apparatus of the type wherein a photographic processing drum is provided for utilizing and discharging successively received unit charges of photographic processing liquid and wherein a container is provided for storing a unit charge of photographic processing liquid to be received by said drum, the improvement which comprises: means for tempering a unit charge of photographic processing liquid within said container to a predetermined temperature above that temperature which is optimum for photographic processing; and means for varying the predetermined temperature of the unit charge of photographic processing liquid within said container in inverse proportion to changes in the ambient temperature immediately surrounding the drum in a manner such that the predetermined temperature exceeds the optimum temperature by an amount resulting in an average photographic processing temperature which is substantially the same as the optimum temperature. 